The most important aspect of a Muslim's deeds is his intention.

Narrated 'Umar bin Al-Khattab:

I heard Allah's Messenger (ﷺ) saying, "The reward of deeds depends upon the intentions and every person will get the reward according to what he has intended. So whoever emigrated for worldly benefits or for a woman to marry, his emigration was for what he emigrated for.
"(Sahih al-Bukhari 1, Book 1, Hadith 1)

If someone has bad intentions while performing a good deed, that good deed may not be beneficial to him in the afterlife courtroom.
Similarly, the intention of Umrah is extremely essential. And, if you're thinking to perform Umrah, make it your primary goal to atone for earlier sins. Accept your misdeeds or sins with a clear intention.